Adjustable hacksaw frame



July 12, 1960 A. L. JOHNSON 2,944,574

ADJUSTABLE HACKSAW FRAME Filed Jan. 30, 1958 2 Sheets-Sheet 1 INVENTOR ALVIN L. JOHNSON ATTORNEY y 1 1960 A. L. JOHNSON 2,944,574

ADJUSTABLE HACKSAW FRAME Filed Jan. 30, 1958 2 Sheets-Sheet 2 INVENTOR ALVIN L.JOHNSON ATTORNEY P 4. Patented, July 12,1960

7 2,944,574 ADJUSTABLE HACKSAW FRAME Alvin L. Johnson, Worcester, Mass., assignor to Johnson Enterprises, Inc., Worcester, Mass, a corporation of Massachusetts Filed Jan. so, 1958, Ser. No. 712,225 4 Claims. c1.14s--s4' This invention relates to a new and improved adjustable hacksaw, and the principal object of the invention resides in theprovision of new and useful means for imparting a tension to the hacksaw'blade, said means being incorporated in a relatively simple and easily manufactured frame of novel construction whereby a mere turning of a nut or the like results in a continuous, smooth adjustment of the tension to the degree desired as contrary to the prior art addition or increase of tension by steps; and the provision of a hacksaw as abovestated including means for adjustment of the frame whereby hacksaws of different lengths may be utilized in the same frame by a simple, easy and quick adjustment thereof.

Further objects of the invention include the provision of an adjustable hacksaw as above described including a frame having a handle and a telescopic end piece slidingly associated with said frame, in combination with means mounted on said frame and engaging the telescopic end piece for quick and easy adjustment thereof relative to the frame for varying the tension upon a'hacksaw blade member between the end-piece and the handle of the frame.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a view inelevation of one form of the invention;

Fig. 2 is an enlarged section on line 2-2 of Fig. 1',

Fig. 3 is a section on a reduced scale on line 3-3 of Fig. 2; r

Figs. 4 and 5 are sections on the respective lines of Fig. 2;

Fig. 6 is a view in elevation of a modified form of the invention; 7

Fig. 7 is an enlarged section on line' 77 of Fig. 6;

Fig. 8 is a section on a reduced scale on line8-8 of Fig. 7; and

Figs. 9 and '10 are sections on the respective lines in Fig. 7.

In carrying out the present invention, I provide a relatively simple but comfortable hand and finger protecting vided with'siinilar pins as at 26 fora like, purpose and it will be clear that the;hacksawblade, which has holes at the ends thereof, may be mounted on said pins as shown in Fig. 1.

An elongated screw rod or the mounted within the combined tubes as is clearly shown in Figs. 2 and 3, and this elongated screw rod is meshed with a nut 30 held in fixed relation to the inner tube 18 bya set-screw or similar means 32. The screw rod 28 is rotatable by a finger piece 34 pinned or' otherwise secured theretoand is held against longitudinal motion by any desired means such as adjustable set-screws 36 mounted at the rear end ofthe tube 16 as plainly shown in Fig. 2. These set-screws have rounded noses engaged in an annular recess 37 in rod 28.

It will-be seen that when the screw is rotated, the nut tube 18 and'this action provides for extensionof'the member 18,'thus imparting a tensionon the hacksawv blade, maintaining the same in position. The pin 38 extending through the tube 16 and into a slot 40 maintains the tube 18 against rotation.

In the other form of the device shown in Fig. 6, a handle 42 similar to that at 10 may be utilized, and this handle is also provided with a sleeve or ferrule 44 which, however, is slotted at 46 to accommodate a radially extending thumbnut 48.

The thumbnut 48 is secured to an elongated screw rod 50 in mesh with a nut 52 secured at 54 to an inner and smaller sleeve 56, so that when the thumbnut 48 is rotated, the nut 52 and hence sleeve 56 will be advanced or retracted in order to provide tension or release the same on the hacksaw blade 58. The tube 56 is conveniently telescopingly arranged in another larger tube 60 and may be provided with a pin or the like 62 maintaining the same against rotation by being received in a slot 64 in the smaller tube 56.

It is to be noted that a left-hand thread is preferably used on the screw shaft 50 and for this reason the nut 52 and inner sleeve 56 are moved outwardly when the thumb and forefinger are applied to the thumbnut 48 in the usual manner. V

It will be seen that this invention provides a very simple but effective hacksaw frame which may be extended to accommodate blades of many difierent lengths as indicated by-the relative solid and dotted lines in Figs.

1 and 6 and at the same time by a very simple and effective means a continuously increasingtension is applied to the blades so that any degree of tautness may be achieved as desired without the necessity of applying the tension by steps.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A hacksaw comprising a handle, means on said 7 handle mounting a tubular member in fixed relation as at 20 to provide a relatively elongated hook or termithereto, a second tubular member telescopingly associated with the first tubular member, means on the handle and the second tubular member for engaging and holding a hacksaw blade, and means associated with the first-named tubular member for extending and retracting the secondnamed tubular member with respect thereto, said lastnamed means comprising an elongated screw rod located within the tubular members and engaging a nut fixed to the second-named tubular member, means to restrict longitudinal motion of the screw rod, and means to ro' tate the screw rod.

2. The hacksaw of claim 1 wherein said screw rod is left-hand threaded. r

like 28 is preferably 3. The hacksaw of claim 1 wherein the nut mounted on. the screw rod is supported on the handle of the hack:

saw.

4. The hacksaw of claim 1 wherein the means for turning the screw rod is mounted directly thereon at the rear Qi he nee le. said fiI P=Fl tu la embe e t nd to the ea 9f th nvfi References Cited in the file of this patent UNITED STATES PATENTS Curry June 1, 1943 Dohner Jan. 1, 1952 Bouschor Sept. 30, 1952 Dreier June 18, 1957 

